Safety switch-lock.



G. MARSHALL.

SAFETY SWITCH LOOK.

APPLIOATION IILED JULY 1a, 1911.

Patented May 21, 1912.

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COLUMIIA 'LANOGIAPH 00., WASHINGTON. n. L.

G. MARSHALL.

SAFETY SWITCH LOCK.

APPLICATION FILED JULY 19, 1911.

1,026,875. Patented May 21, 1912.

2 SHEETS-SHEET 2.

J/ lllll nNiTED STATES PATENT OFFICE.

GEORGE MARSHALL, OF EAST ELY, NEVADA.

SAFETY SWITCH-LOCK.

To all whom it may concern:

Be it known that I, GEORGE MARSHALL, a citizen of the United States, residing at East Ely, in the county of White Pine and State of Nevada, have invented new and useful Improvements in Safety Switch-Locks, of which the following is a specification.

This invention relates to improvements in safety switch locks and it proposes a device which is to be associated with the operating lever of a switch stand of any usual construction and which can be operated to release the lever only by means of an appropriate key.

With the key controlled switch locks ordinarily employed, no provision is made against the removal of the key from the lock in an unlocked position of the operating lever and the keys are carried away by trainmen before the switch is locked and are frequently lost by dropping from the lock during the movement of the lever, especially where the switching is heavy at any one point and the lever is not locked during its use.

The primary object of the invention is to provide a switch lock of such construction that it is impossible to remove the key from the lock except when the operating lever is locked to the switch stand, even by the use of jimmies or similar devices.

A further object of the invention is to provide a switch lock of such construction that successive switching operations may be carried on at any point where the tra'thc is heavy and without the necessity of locking the operating lever after each operation and without any liability of losing the key.

Other objects and advantages will be apparent as the description proceeds.

An embodiment of the invention is illustrated by way of example in the accompanying drawings, wherein Figure 1 is a side elevation showing the practical application of the device to a switch stand of well known form. Fig. 2 is a plan View showing the inclosed operatin parts of the lock in the positions which tey occupy in an unlocked position of the operating lever. In this figure, the casing which incloses the operating parts is shown in section. Fig. 3 1s a longitudinal sectional view showing the parts in the same relation as in Fig. 2. Fig. 4 is a cross sectional view on the line 44 of Fig. 2. Fig. 5 is a cross sec- Specification of Letters Patent.

Application filed July 18, 1911 Patented May 21, 1912.

Serial No. 639,169.

tional view on the line 55 of Fig. 2. Fig. 6 is a perspective view showing in dissociated relation, but in the order of their assemblage, two cooperating latch devices to be specifically described. Fig. 7 is a side elevation of the operating parts with the lever and the casing in section and the operating parts in the positions which they occupy in the locked position of the operating lever. Fig. 8 is a plan view similar to Fig. 2, but showing the operating parts in the same relation as Fig. 7. Fig. 9 is an enlarged side elevation of the lock showing the keyhole thereof and, by dotted lines, the relation of the operating parts and the key in an unlocked position of the operating lever.

Similar characters of reference designate corresponding parts throughout the several views.

The switch stand shown in Fig. 1 is of well known construction, and comprises the base a which has a square socket to conformably receive the square boss on the rotatable casting 6. The casting b rests upon a vertical shaft 0 which is operatively connected to the switch in the well known manner. The switch (not shown) is operated by the lever (Z having a forked inner end which is pivoted to the shaft 0. The lever '(Z is operatively connected by links 0 to the casting b, the pivotal connection of the links 6 and said lever comprising a bolt f.

The switch lock is designated generally by the letter A and is mounted upon the switch operating lever. The switch stand described in the foregoing paragraph is generally known as the Buda stand, and its rotatable casting b is provided with a fixed hasp g which, when the lever d is in position to be locked, projects through an opening it in said lever. Ordinarily a padlock is employed to lock the lever (Z, the bail of the padlock being passed through the eye L of the hasp. The switch lock A, which forms the subject of the present invention, is employed as a substitute for the ordinary padlock and, when applied to the Buda stand, its operating parts coact with the hasp g in a manner to be described. It is to be understood, however, that the disclosure of the look A in connection with the Buda switch stand is merely by way of example and that the lock may be employed with equal facility and advantage in connection with switch stands of other types.

The operating parts of the switch lock are mounted upon a base plate 1, and are inclosed in a casing 2 which isbolted or otherwise secured to the base plate. The base plate 1 has an opening 3 which alines with the opening 72, in the lever (Z and through which the hasp 9 passes as said lever comes into its lowermost posit-ion.

It will be apparent from the description thus far given that the switch lock is of unitary self contained nature, and consequently it may be readily applied to the operating lever of an existing switch stand without requiring any modification or disassemblage of the latter. When used in con nection with the Buda stand, the base plate 1 preferably has at one end thereof an extension 4 and at its other end a down wardly inclined hook 5. The hook 5, is engaged over the pivot bolt f previously referred to and the extension 4 is clamped to the lever by means of a suitably shaped ring 6, which is fitted upon the lever and carries a clamping screw 7 for engagement with said extension.

The element for locking the lever (Z to the casting Z2 consists of a tumbler 8 which has an approximately semicircular curvature and is pivoted at one end, as at 9, to the base plate 1, for movement in a plane parallel to the plane of the base plate. In its locking function, the free end of the tumbler 8 passes through the eye Z: of the hasp g and the tumbler is operated in this function by a retractile coil spring 10, one end of which is secured to the base plate and the other end of which is secured to a pin 11, carried by said tumbler. The tumbler is preferably steadied in its operating. movement by a suitable keeper 12, which is secured to the base plate.

The mechanism for disengaging the tumbler from the hasp and thereby unlocking the lever (Z consists preferably of a slide 13, and the pin 11 also serves as a connection between said tumbler and said slide and passes through a transverse slot 14 in the latter. The slide 13 has its underface provided with rack teeth 15 and is operated by a dished pinion 16. The pin 17, upon which the pinion 16 is mounted, is carried by a bracket 18 which has at its upper end a keeper flange 19 and the slide 13 is arranged immediately under and is steadied by this flange. The bracket 18 also has a flange 20, adjacent the flange 19 for a purpose which will presently appear. The pinion 16 is operated by a key 21, (Fig. 9) which is inserted through a keyhole 22 in the casing 2, and is fashioned to engage between suitably spaced lugs 23, provided on the inner circumferential face of the pinion 16. The parts are so related that when the tumbler 8 is in its locking position the space between the lugs 23 alines with the keyhole 22, thereby permitting the removal of the key 21 but when the tumbler 8 is not in its locking position, the lugs 23 are out of alinement with the keyhole and conse-' quently the key cannot be removed.

The invention includes means for latching the tumbler 8 against movement to its locking position in any position of the lever (Z except that in which the hasp g has passed as far as possible through the open ings h and 3 and the said means is operated to release the tumbler by said hasp and is of such nature that it cannot be so operated except by the hasp. In the embodiment disclosed the latching means includes three latch elements, 24, 25, and 26, respectively, the element 24 being a main latch, the element 25 an auxiliary latch, and the element 26 a supplemental latch. The purposes and operations of these several latches will appear as the description proceeds. The latch 24 is pivoted, as at 27, to the base plate 1 for movement in a plane parallel to the plane of saidplate and has at its free end a bill 28 for latching engagement with a shoulder 29, provided in the tumbler 8, adjacent the pivot 9, thereof. The latch 25 is held in latching engagement with said tumbler by a suitable leaf spring 30, which is secured to the plate 1 and bears with its free end against the bill 28. The face of the latch 24, which overhangs the opening 3, is formed on an inward and downward bevel as at 31, and is engaged by the hasp g, the bevel face 31 being in effect a cam face. The auxiliary latch 25 does not act directly on the tumbler 8 but on the latch 24 and is disposed substantially transversely to the latter, being pivoted at 32 to the plate 1 for movement in a plane parallel to said plate. The latch 25 has a raised finger 33 adjacent its pivot for engagement in a recess 34 in the latch 24. The latter has a recess 35 in its under face to provide for the necessary movement of the latch 25. The movement of the latch 25 to its operative position with respect to the latch 24 is produced by a suitable coil spring 36, and the movement of the latch 25 to permit of a releasing movement of the latch 24 is produced by the hasp g which engages a bevelor cam face 37 of the latch 25. The latter has an extension 38 which engages against a shoulder of the keeper 12 and thereby limits the movement of the latch 25 by the spring 36. The supplemental latch 26 engages directly with the tumbler 8 and is pivoted at 39 to the bracket 18 for movement in a plane perpendicular to the plate 1. The latch 26 is provided on its under face with a pin 40 for engagement in a recess 41 in the edge of the tumbler, and is acted on by a coil spring 42, which is positioned against the flange 20. At the free end of the latch 26 a lip 43 is provided, which overhangs the opening 3 and is engaged by the hasp g. The latch 26 is preferably steadied by a suitable keeper 44.

In operation, the lever cl is raised to dis- 5 engage the casting b from its base 8 and thereafter said lever is turned and produces a corresponding movement of the shaft 0 to set the switch in the well known manner. It will be apparent that it is not necessary 10 to lock the lever (Z after each operation and that successive switching operations may be carried on with facility. However, in the operative movements of the lever (Z the key is positively held in such position that it cannot drop from the look as has been explained. To remove the key from the lock, it is necessary to lock the lever (l to the casting b and for this purpose said lever is lowered with considerable force as far as it will go, and as the hasp passes through the openings h and 3 it will act on the various latches and thereby ultimately enable the spring 10 to producea locking movement of the tumbler 8, as has been explained, at which time the key may be removed from the lock. As the hasp g enters the lock, it first engages the latch 25, moving the latter against the tension of its spring 36 until the finger 33 alines with the recess 34, and thereby permits a releasing movement of the latch 24. Thereupon the hasp effects such releasing movement of the latch 24, moving the latter against the tension of its spring 30. After the latch 24 has been disengaged from the tumbler 8 in the manner explained, the hasp, as it is ust about completing its relative inward movement, acts upon the latch 26 and at such time the spring 10 snaps the tumbler 8 into engagement with the eye 70, and resets the slide 13 and pinion 16 as is manifest. To unlock the lever cl, the key 21 .is employed to turn the pinion 16 and through the agency of the slide 13 to withdraw the tumbler from the eye it and thus permit the lever (Z to be raised. Just as soon, however, as the latches referred to are disengaged by the hasp consequent to the raising of the lever cl their several springs snap them into operative relation, the latch 24 engaging the tumbler, the latch 25 engaging the latch 24, and the latch 26 likewise engaging the tumbler, as has been explained.

A fraudulent manipulation of the device is practically impossible. In the first place, the spring 30, which engages the latch 24, is very strong, and considerable force, if applied at the spring, is necessary to move the latch 24, though the force required, if applied at the end of the lever cl, is reduced by about half. In the second place, before the latch 24 could be manipulated, it would be first necessary to manipulate the latch 25, and these operations would require two 65 jimmies and would be so difficult that a trainman would prefer to obtain his key in the proper and easier way. Assuming, however, that the two latches 24 and 25 were, perchance, manipulated, the tumbler would still be held by the latch 26 and the oper ation of this latter, while still holding the latches 24 and 25 released, would present practically insuperable difficulties.

It will be understood that no specific description herein contained, either as to use or structure, is intended to put any limitation upon the scope of the appended claims, which does not inhere in the language thereof. It will also be understood that the word hasp as used in the claims and other language peculiar to the environments disclosed, is applicable to equivalent or analogous parts which might be employed in other environments for which the improvement might be adapted.

Having fully described my invention, I claim:

1. The combination with a switch operating lever of a switch lock associated therewith and a hasp for cooperation with the lock to secure the lever against movement, the lock including a movable tumbler for locking engagement with the hasp, a spring for moving the tumbler to its locking position, key operated means for moving the tumbler against the tension of its spring, a

spring pressed latch for engagement with the tumbler to prevent an operative movement thereof, the latch being operable by the hasp to release the tumbler, and a casing inclosing the lock parts aforesaid, the casing having a keyhole through which the key may be inserted but from which the key may not be removed so long as the latch is in engagement with the tumbler.

2. The combination with a switch operating lover of a switch lock associated therewith and a hasp for cooperation with the lock to secure the lever against movement, the lock including an approximately semicircular tumbler for locking engagement with the hasp, a spring for moving the tumbler to its locking position, key operated means for moving the tumbler against the tension of its spring, a spring pressed latch for engagement with the tumbler to prevent an operative movement thereof, the latch being operated by the hasp to release the tumbler, and a casing inclosing the lock parts aforesaid, the casing having a key-hole through which the key may be inserted but from which the key may not be removed so long as the latch is in engagement with the tumbler.

3. The combination with a switch operating lever of a switch lock associated therewith and a hasp for cooperation with the lock to secure the lever against movement, the lock including a movable tumbler for locking engagement with the hasp, a spring for moving the tumbler to its locking position, key operated means for moving the tumbler against the tension of its spring, a spring pressed latch for engagement with the tumbler to prevent an operative move ment thereof, the latch being operable by the hasp to release the tumbler, an auxiliary spring pressed latch normally engaging the first named latch to hold the latter from movement against the tension of its spring and being also operable by the hasp to permit of a subsequent releasing movement of said first named latch by said hasp, and a casing inclosing the lock parts aforesaid,

the casing havinga keyhole through which, the key may be inserted but from which the key may not be removed as long as the latch is in engagement with the tumbler.

4E. The combination with a switch operating lever, of a switch lock associated therewith and a hasp for cooperation with the lock to secure the lever against movement, the lock including a movable tumbler for locking engagement into the hasp, a spring for moving the tumbler to its locking position, key operated means for moving the tumbler against the tension of its spring, a spring pressed latch for engagement with the tumbler to prevent anoperative movement thereof, the latch being operable by the hasp to release the tumbler, a supple mental latch also engaging the tumbler to hold the latter against movement by its spring and operable by the hasp t'o disengage the tumbler subsequent to the similar operation of the first named latch by said hasp, and a casing inclosing the lock parts aforesaid, the casing having a keyhole through which the key may be inserted but from which the key may not be removed so long as the latch is in engagementwith the tumbler.

5. The combination with a switch operat ing lever of a switch lock associated therewith and a hasp for cooperation with the lock to securethe lever against movement, the lock including a movable tumbler for locking engagement wit-h the hasp, a spring for moving the tumbler to its locking position, 'key operated means for moving the tumbler against the tension of its spring, a

spring pressed latch for engagement with the tumbler to prevent an operative movement thereof, the latch being operable by the hasp to release the tumbler, an auxiliary spring pressed latch normally engaging the first named latch to hold the latter from movement against the tension of its spring and being also operable by the hasp to permit of a subsequent releasing movement of said first named latch by said hasp, a supplemental latch also engaging the tumbler GEORGE MARSHALL. WVitnesses A. D. CARPENTER, F. L. MILLER.

Copies of thiS-patentmay be obtained for five cents each, by addressing the Commissioner of .Patents, Washington, D. G. 

